Anti-Biofilm and Anti-Hemolysis Activities of 10-Hydroxy-2-decenoic Acid against Staphylococcus aureus

Round 1

Reviewer 1 Report

Reviewing report of the manuscript ID: Molecules-1595499-peer-review-v1

The authors have done a very well job regarding the research work performed in the Manuscript submitted to molecules for publication. The research work done implie the following research points:

1. They have used 10-Hydroxy-2-decenoic acid (10-HDA), which named as Royal Jelly acid, to explore its effect on the biofilms and virulence of aureus and its potential molecular mechanism.
2. Quantitative crystal violet staining indicated that 10-HDA significantly reduced the biofilm biomass at sub-MIC levels (1/32MIC to 1/2MIC) and carried out a comparative study between the Effect of 10-HDA on the Growth of Planktonic Bacteria and Biofilm Biomass, studying Effect of 10-HDA on the Morphology of S. aureus Biofilms as well.
3. Scanning electron microscope (SEM) observations demonstrated that 10-HDA inhibited the secretion of extracellular polymeric substances, decreased bacterial adhesion and aggregation, and disrupted biofilm architecture.
4. 10-HDA could significantly decrease the biofilm viability and effectively eradicate the mature biofilms.
5. The hemolytic activity of aureus was significantly inhibited by 10-HAD as well.
6. qRT-PCR analyses revealed that the expression of global regulator sarA, agrA, and α-hemolysin gene hla were down regulated by 10-HDA.

Concluding that that, 10-HDA could be used as a potential natural anti- microbial agent to control the biofilm formation and virulence of S. aureus.

The work has been systematically designed and well formulated, and I recommend its publication in the present form.

Author Response

Thank you very much for your appreciation.

Reviewer 2 Report

The submitted work evaluated the anti-biofilm and anti-hemolysis activities of 10-hydroxy-2-2 decenoic acid against Staphylococcus aureus. The authors pointed out the following findings:

- the inhibitory effect of 10-HDA on S. aureus biofilm formation was attributed to the anti-biofilm ability of 10-HDA rather than the inhibition of the bacterial growth,

-10-HDA inhibited EPS production, decreased bacterial adhesion and aggregation, and disrupted biofilm architecture

-10-HDA had a significant inhibitory effect on the cell viability of S. aureus during biofilm formation

-10-HDA could reduce EPS production to prevent the formation of biofilms,

- 10-HDA could effectively eradicate the mature biofilms and reduce the bacterial viability of mature biofilms.

-10-HDA has a strong inhibitory effect on hemolysin production in S. aureus.

-10-HDA inhibits the biofilm formation and hemolytic activity of S. aureus by repressing the transcription of sarA, agrA, 183 and hla.

The methodology of the work is correct and the findings are supported by the results.

I recommend the publication of the work.

Author Response

Thank you for your kind comments. We have carefully corrected the typos and grammatical errors which are highlighted in the manuscript.